This invention relates generally to expansion joint seals of the type used for sealing an expansion joint space or gap against the intrusion of dirt, water and other debris as for example might be encountered by expansion joints employed in roadway construction. More specifically, the present invention relates to an elastomeric expansion seal that may be employed in a joint assembly having elongated, metal edge members installed on either side of the gap as defined by a pair of structural members such as concrete slabs wherein the seal is connected between said edge members.
The subject invention includes mounting beads for affirmatively locking the longitudinal edges of the seal disclosed herein within edge member cavities being correspondingly formed therefor. Such mounting beads, and the edge members formed to cooperate therewith, are disclosed in applicant's U.S. Pat. No. 3,994,609 issued Nov. 30, 1976 and U.S. Pat. No. 4,067,660 issued Jan. 10, 1978, both being assigned to the assignee of the instant invention. The seals disclosed in applicant's aforesaid patents are generally known in the trade as "strip seals" in that they have a single seal wall disposed across an expansion gap and which is connected to both of the mounting beads.
The present invention, while incorporating mounting beads as considered hereinabove, involves a more substantial seal construction for spanning the gap between the beads.
An ever present concern in utilizing seals such as that considered herein which may be used in a roadway, is to protect the same against tears, damage and leaks. In considering such potential occurences with respect to the use of a seal, the instant invention provides a construction which more effectively, and with a high degree of dependablity, overcomes such potential problems.
The prior art has considered the placement of upper and lower walls in an expansion seal for purposes of spanning an expansion gap, such as that shown in U.S. Pat. No. 4,007,994--Brown, issued Feb. 15, 1977. However, the mere placement of an upper and lower wall across an expansion gap which undergoes considerable variations with respect to the width thereof, does not yield the predictability and dependability of wear and movement as found in the construction of the instant invention.